She is expected to ask for more visas for foreign aid workers as the Syrian Arab Red Crescent struggles to distribute food.

The UN says an estimated two million Syrian civilians have now been affected by the crisis and more than one million have fled their homes.

Tens of thousands of people have fled across Syria’s borders into Turkey, Jordan, Lebanon and Iraq amid continuing violence across the country.

In another development, foreign ministers of the Islamic Co-operation Organisation (OIC) have called for Syria to be suspended from the 57-nation bloc at an emergency two-day summit in Mecca, Saudi Arabia, which starts on Tuesday.

Only ministers from Algeria and Iran, which is regarded as Syria’s closest ally, were against the recommendation, reports say.

“We certainly do not agree with the suspension of any OIC member,” Iranian Foreign Minister Ali Akbar Salehi said after a preliminary meeting in the city of Jeddah on Monday.

“We have to look for other ways, means and mechanisms for resolving conflicts and crises,” he said.”